Autopilot Disabled at Low Temperatures? I started a trip this morning with a cold soaked car - parked outside overnight, with outside temperature around 25 F. Power and regen were limited as expected. Got on the highway and while TACC was available, but autopilot was not. (Attempting to engage autopilot with double pull on stalk resulted in the error message "Autopilot temporarily unavailable" and no grey steering wheel icon displayed) After about 45 minutes, with outside temperature at 28 F and battery warmed enough to show full regen, autopilot became available (icon appeared) and would enable. As I remember the temperature had briefly showed as 28 F a bit earlier while regen was still limited to about 50 kW but then dropped again. I can't imagine why autopilot would depend on having full regen, so I expect that temperature is the key variable. Either the temperature needs to be above some threshold for a minimum time or the threshold is between 28 and 29 F the first 28 F was below this threshold. That said, it would make some sense to disable autopilot in icy conditions since that is likely beyond the current hardware and software, and temperature is a simple proxy. I am at a loss to explain why the threshold temperature is 28 F rather than freezing (32 F). For completeness, all the sensors were free of snow or ice and the road was clear and dry, with 6+ inches of snow past the highway shoulders. Some dirt on the windshield, driving south into the sun at between 10 and 11 AM, so glare could have been a problem for the camera, but this remained the same throughout the observation period and seems secondary. I've read of snow/ice blocking the radar sensor and disabling both TACC and autopilot, but that does not apply in this case. Any other similar experiences out there?